1. Field of the Invention
This invention relates to an improvement in a crankshaft pulley attached to an end of a crankshaft of an automotive internal combustion engine, and more particularly to the crankshaft pulley formed of sheet metal.
2. Description of the Prior Art
Automotive internal combustion engines are provided with crankshaft pulley fixedly attached at one end of a crankshaft. For example, in overhead camshaft engines, the drive of a camshaft has been conventionally achieved by the crankshaft pulley through a chain passed on both the camshaft and crankshaft pulley. In recent years, a cogged belt (cogged timing belt) is used extensively in place of the chain, which cogged belt is passed over a toothed pulley of the crankshaft pulley. However, such a crankshaft pulley is usually formed of cast iron or sintering metal, and therefore is larger in weight, thereby preventing engine weight reduction. Besides, the rigidity of the crankshaft pulley is not high enough to justify its larger weight.